Flasher sounder



J. W. WELSH FLASHER SOUNDER Filed Sept. 5, 1956 Sept. 17, 1957 I I 45sL-z'fi 7 INVENTOR.

- ATTORNEY FLASHER SOUNDER James William Welsh, Summit, N. J., assignorto Signal Stat Corporation, Brooklyn, N. Y., a corporation of New YorkApplication September 5, 1956, Serial No. 605,010

6 Claims. (Cl. 200-122) This invention relates to snap action switches,such as flashers for automotive vehicle signaling systems, and moreparticularly to novel means for producing an audible indication ofoperation of a flasher.

With the increasing importance of turn signal lamps in driving on modernmulti-lane highways, it is correspondingly important that the driver notonly be assured of their proper operation but also be made conscious ofa improper operation. For example, in using a turn signal lamp toindicate a proposed change from one lane to another, the resultantsteering wheel movement is frequently insuflicient to cancel the turnindication when the lane change has been completed. If the driver doesnot cancel the signal manually, following and aproaching vehicles aregiven a wrong indication of the projected movement of his vehicle.

For these reasons, it is considered highly desirable to provide aclearly audible indication of the operation of a turn signal, and thismay be done, with some types of signal systems, by using a flasherproducing a highly audible click as it opens and/ or closes.

In my Patent 2,756,304 dated July 24, 1956, entitled Snap Action Device,,I have shown and described a novel snap action vane which may beincorporated in a snap action switch. This vane is provided with aninitial deformation along a right line extending across the vane bythinning or deforming the vane along this line in two or more spacedsections of the line, these sections being spaced at their inner endsfrom the center of the vane and also preferably spaced from the outerends of the bent line. When such a vane is to be utilized in a snapaction switch, such as a flasher, the vane is bent about another line,at an angle to the line of initial deformation, by applying force to theends of such line. When such force is released, the vane snaps back toits initial position, the action closely resembling .that of a toggle.

The vane is held in the new deformed position by attaching a high,resistance wire or strip at each of its 'ends to the vane at the ends ofthe line of initial deformation. The high resistance wire or strip thusforcibly holds the vane in a distorted position bent about a lineangularly related to the line of initial deformation. When the highresistance wire has electric current passing therethrough, it heats andexpands. During the expansion of the wire, a point is reached at whichthe tension exerted by the wire is over-balanced by the kinetic energyof the vane stored therein by bending the latter from its initialcondition. At this point, the vane snaps back to its initial condition.

As described said patent, the vane has a mounting member secured theretoat a point in an eliptical line representing the distribution ofstresses adjacent the vane center due to the initial deformation of thevane. This mounting member extends across the high resistance wire andcarries a contact cooperative with a contact carried by a highresistance wire. When the vane is in the deformed position, .in which itis vheld by the contracted high resistance wire, these two contacts arein engagement, so that current from a source of electric power connectedto a contact carried bythe mounting member flows .in

nited States Patent parallel paths through the high resistance wire,through the vane, and thence to the other terminal of the currentsource. When the vane snaps back to its initial condition as a result ofheating and expansion of the wire, the contacts separate and the highresistance wire then cools and contracts. During such contraction theforce exerted by the wire overbalances the force tending to maintain thevane in its initially deformed condition, and the resultant toggleaction snaps the vane to the deformed condition re-engaging the contactcarried by the resistance wire with the contact carried by the mountingmember for the vane. The electrical circuit is thus reclosed and thecycle repeats.

This snap action switch provides a rugged, compact and efficientflasher. However, the flasher is relatively quiet in operation so thatthere is substantially no audible indication of its operation. Thepresent invention is directed to novel means for providing such audibleindication.

During snapping of the vane about its mounting point, there is a verysubstantial displacement of the vane corners relative to the centralpart of the vane. This relatively large magnitude movement of thecorners is utilized to vibrate a tuning fork element each time the vanesnaps between a stress-deformed condition and a pre-set position.

More specifically, the spring metal of the vane is relatively hard. Byproviding a thin strip of similarly hard metal and welding one end ofthis strip to a vane corner so that the strip extends across thedeformation to the diagonally opposite corner, the free portion of thestrip may be set into vibration each time the vane snaps. As the vanesnaps, the strip, previously lying against the vane, is set intovibration as a tuning fork due to the kinetic energy developed in itsfree end as the vane snaps. A similar vibration is set up in the stripas the vane snaps back. The vibration of the tuning fork strip providesan audible indication of operation of the flasher.

For an understanding of the invention principles, reference is made tothe following description of a typical embodiment thereof as illustratedin the accompanying drawing. In the drawing:

Fig. 1 is a perspective view of a snap action vane and mounting memberused in the invention flasher;

Fig. 2 is a top plan view of a snap action flasher embodying theinvention;

Fig. 3 is a similar view, with a part of the vane cut away to illustrateits support; and

Fig. 4 is a schematic wiring diagram of a signal system embodying theinvention flasher.

Referring to Fig. l, a snap action vane 10 is illustrated which isidentical with that shown and described in Patent No. 2,756,304. Vane 10is preferably made of relatively thin spring metal, with considerationbeing given to its spring factor, stiffness, temperature coeflicient,and the like, in accordance with the desired rate of operation of thesnap action.

To provide an initial set to vane 10 and to give the same some depth sothat it will resemble a beam in its action, the vane 10, which is shownas a substantially rectangular vane, is deformed or thinned along adiagonal interconnecting corners 11 and 12. This vane deformation ispreferably effected by lineally embossing the vane along the line 11--12in two elongated spaced portions or bosses 15. It will be noted that thebosses 15 have their inner ends disposed substantially equal distancesfrom the center of vane 10 so that the center area of the vane is leftunmarred. As explained in said Patent No. 2,756,304, this greatlyprolongs the life of vane 10 by removing the stress concentration fromthe center to a pair of points on bosses 15. If the deformation lines1112 were continuous through the vane center area, the flattening of thevane at the center during repeated cycles would eventually cause fatigueof the vane at the center and reduce the amount of force required tosnap the vane between the illustrated position and another deformedposition. Due to the bosses 15, 15, the sections 13 and 14 of the vaneon either side of line 1112 bend upwardly so that the vane assumes theform of a shallow V having its apex on line 11-12. When vane bendingforces are applied to the end of lines 1112, and the value of theseforces equals or over-balances the inherent tendency of the vane to stayin its preset condition, the vane snaps into a new bent or deformedposition, forming another shallow V along the other diagonal 1.6-4.7.When the forces at points 11 and 12 are decreased to a point where theyare overbalanced by the kinetic energy stored in vane due to suchdistorting force, the vane snaps back to a position bent along the lines1112.

Photographs, taken with polarized light, of a transparent vane formed inthis manner show lines of force in the unmarred center area of the vanewhich comprise elliptical bands having radii centered on the vanecenter. If the vane is secured or supported at a point on one of theseelliptical stress loci, the stress points on the vane during applicationof bending force at corners 11 and 12 occur within the lengths of bosses15. Thus, the stresses are removed from the center area and distributedbetween two points spaced from the center. This greatly prolongs theperiod before fatigue takes place in the stressed section of the vane.As described in said Patent No.

2,756,304, advantage is taken of this fact by supporting the vane bysecuring the latter, at a point of one of such elliptical lines offorce,to a relatively rigid electrically conductive metal mounting member 20.The point of attachment of the mounting member to the vane acts as apivot point for the vane during its snap action and is preferably spacedlaterally of the initial bend line 11--12.

When the vane is used to form a snap action switch, the bending stressesmay be conveniently applied to points 11 and 12 by means of a highresistance wire or strip 30 secured to these corners of the vane. Forthis purpose, the points 11 and 12 are bent downwardly as illustrated inFig. 1, and the ends of wire or strip 30 are secured thereto at 31 and32, while the vane is bent along the line 16-17, so that the wire in itscold or contracted position holds the vane deformed into a V having itsapex along line 1617. If wire 30 has electric current passedtherethrough, it expands and, as the wire force is overbalanced 'by therestoring kinetic energy built up in vane 10, the

vane snaps back to its initially bent condition along the line 11--12.

An arrangement for utilizing this action is illustrated in Figs. 2 and3, which show the invention snap action switch. The center section 21 ofmounting member has a band 23 of insulation wrapped thereon and a band24 of conductive metal is wrapped around band 23. Band 24 carries acontact point 25 at the intersection of mounting member 20 and wire 30.The wire has a contact point secured to its mid-section for cooperationwith contact 25.

The free end of mounting member 20 is secured to a dielectric base as bya rivet connecting the outer end 26 of member 20 to a prong or terminal42 on base 40. Another prong or terminal 33 is connected by rivet 34 -toa conductive strip 47 connected to band 24.

In accordance with the invention, a thin strip 50 of hard spring metalhas one end welded, brazed or otherwise '10 thus bends, the free end 51of strip 50 moves away from the vane surface. After sufficient expansionof wire 30, vane 10 snaps to the restored position, snapping end 51 ofstrip 50 further away from the vane. The resultant kinetic energy instrip 50 sets the strip to vibrate like a tuning fork, producing apronouncedly audible sound.

When wire 30 cools and contracts, vane 10 is snapped back to theillustrated stress-deformed condition, thus snapping strip end 51 towardthe vane surface. Strip 50 is again set into vibration to produce anaudible indication of flasher operation. Thus, on each snapping of vane10, strip 50 is set into vibration, whereby a nearly con tinuous, butundulating, hum is produced which is readily audible to the driver.

The alternate heating and contraction of wire 30 to snap vane 10 isproduced by closure of a signal circuit, such as illustrated in Fig. 4;

Referring to Fig. 4, a grounded battery 44 is connected, through asignal lamp control switch 45 and conductor 40, to terminal 42, and thusthrough bracket 20, vane 10, and wire 30 to contact 35; A conductor 46connects terminal 42 and thus contact 25 and strip 47, to parallel andgrounded signal lamps SL-l and SL-2.

When switch 45 is closed, current flows from battery 44 through switch45 conductor 43, bracket 20, and contact point 35 into contact point 25on band 24. The current flowing through wire 30 causes the latter torapidly heat and expand, this wire preferably being Nichrome wire. Aswire 30 expands and thus lengthens, the force exerted by the wire isfinally overbalanced by the kinetic energy storedin vane 10, and thelatter snaps to its initial or restored position. Thus pulls wire 30downwardly relatively to bracket 20, and snaps contacts 25 and 35 apartto break the electrical circuit. The wire 30 then cools and contracts.As the force exerted by the contracting wire overbalances the forcetending to maintain vane 10 in its restored position, the vane againsnaps to a position bent along line 16-17 wherein wire 30 snaps towardbracket 20 to re-engage contacts 25 and 35. The cycle then repeats, andas the vane snaps from its respective positions, the strip 50 isvibrated and the desired audible sound effect is produced in synchronismwith the change in visual signaling effects.

If desired, a pilot lamp operation may be incorporated in the flasher inthe manner illustrated, for example, in my U. S. Patent No. 2,706,226.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application of the inventionprinciples, it will be understood that the invention may be embodiedotherwise without departing from such principles.

I claim:

1. A snap action electric switch comprising, in combination, adielectric base; a substantially fiat vane of electrically conductiveresilient material having a substantially linear preset deforrnationextending thereacross, said deformation being interrupted intermediateits ends at points substantially equi-distant from the vane center toleave the central area of the vane free of preset deformation; a bracketsecured to said vane at a vane mounting point spaced laterally from saiddeformation; means operable to alternately apply and release vanebending stresses at points adjacent the outer ends of said deformationto eifect snapping of the vane between a stressdeformed position inwhich the vane is bent along a line substantially perpendicular to saiddeformation and a preset restored position in-which the vane is bentalong said deformation; the free portion of the vane, during suchsnapping action, pivoting about such mounting point, a corner of saidvane moving substantially, relative to the vane mounting point, duringsuch snapping; and means secured to said corner for movement therewith,and set into vibration each time the vane snaps to produce an audibleindication of snapping of the vane.

2. A snap action electric switch comprising, in combination, adielectric base; a substantially flat vane of elec- NJ i tricallyconductive resilient material having a substantially linear presetdeformation extending thereacross, said deformation being interruptedintermediate its ends at points substantially equi-distant from the vanecenter to leave the central area of the vane free of preset deformation;a bracket secured to said vane at a vane mounting point spaced laterallyfrom said deformation; means operable to alternately apply and releasevane bending stresses :at points adjacent the outer ends of saiddeformation to effect snapping of the vane between a stressdeformedposition in which the vane is bent along a line substantiallyperpendicular to said deformation and a preset restored position inwhich the vane is bent along said deformation; the free portion of thevane, during such snapping action, pivoting about such mounting point, acorner of said vane moving substantially, relative to the vane mountingpoint, during such snapping; and an elongated strip of spring metalextending across said vane and secured at one end to said corner formovement therewith, and set into vibration each time the vane snaps toproduce an audible indication of snapping of the vane.

3. A snap action electric switch comprising, in combination, adielectric base; a substantially fiat vane of electrically conductiveresilient material having a substantially linear preset deformationextending thereacross, said deformation being interrupted intermediateits ends at points substantially equi-distant from the vane center toleave the central area of the vane free of preset deformation; a bnacketsecured to said vane at a vane mounting point spaced laterally from saiddeformation; means operable to alternately apply and release vanebending stresses at points adjacent the outer ends of said deformationto effect snapping of the vane between a stress-deformed position inwhich the vane is bent along a line substantially perpendicular to saiddeformation and a preset restored position in which the vane is bentalong said deformation; the free portion of the vane, during suchsnapping action, pivoting about such mounting point, a corner of saidvane moving substantially, relative to the vane mounting point, duringsuch snapping; and an elongated strip of spring metal extending acrosssaid vane and secured at one end to said corner for movement therewith,and set into vibration each time the vane snaps to produce an audibleindication of snapping of the vane, the free end of said strip beingadjacent the diagonally opposite vane corner.

4. A snap action electric switch comprising, in combination, adielectric base; a substantially flat vane of electrically conductiveresilient material having a substantially linear preset deformationextending thereacross, said deformation being interrupted intermediateits ends at points substantially equi-distant from the vane center toleave the central area of the vane free of preset deformation; a firstterminal on said base; an elongated electrically conductive bracketsecured to said vane at a vane mounting point spaced laterally from saiddeformation, and secured at its other end to said first terminal; anexpansible high resistance electric conductor secured at each end tosaid vane adjacent the outer ends of said deformation under tension andparallel to said deformation to bend said vane to a stress-deformedposition in which the vane is bent along the other diagonal of the vane;said vane, upon a predetermined expansion of said conductor, snapping toa preset restored position in which the vane is bent along saiddeformation; the free portion of the vane, during such snapping action,pivoting about such mounting point, a corner of said vane movingsubstantially, relative to the vane mounting point, during suchsnapping; a second terminal on said base; a first contact mounted ininsulated relation on said bracket in alignment with said conductor; asecond contact connected to said conductor and normally engaged withsaid first contact; said contacts being disengaged upon snapping of thevane to such preset restored position; and means secured to said cornerfor movement therewith, and set into vibration each time the vane snapsto produce an audible indication of snapping of the vane.

5. A snap action electric switch comprising, in combination, adielectric base; a substantially flat vane of electrically conductiveresilient material having a substantially linear preset deformationextending thereacross, said deformation being interrupted intermediateits ends at points substantially equi-distant from the vane center toleave the central area of the vane free of preset deformation; a firstterminal on said base; an elongated electrically conductive bracketsecured to said vane at a vane mounting point spaced laterally from saiddeformation, and secured at its other end to said first terminal; anexpansible high resistance electric conductor secured at each end tosaid vane adjacent the outer ends of said deformation under tension andparallel to said deformation to bend said vane to a stress-deformedposition in which the Vane is bent along the other diagonal of the vane;said vane, upon a predetermined expansion of said conductor, snapping toa preset restored position in which the vane is being along saiddeformation; the free portion of the vane, during such snapping action,pivoting about such mounting point, a corner of said vane movingsubstantially relative to the vane mounting point, during such snapping;a second terminal on said base; a first contact mounted in insulatedrelation on said bracket in alignment with said conductor; a secondcontact connected to said conductor and normally engaged with said firstcontact; said contacts being disengaged upon snapping of the vane tosuch preset restored position; and in elongated strip of spring metalextending across said vane and secured at one end to said corner formovement therewith, and set into vibration each time the vane snaps toproduce an audible indication of snapping of the vane.

6. A snap action electric switch comprising, in combination, adielectric base; a substantially flat vane of electrically conductiveresilient material having a substantially linear preset deformationextending thereacross, said deformation being interrupted intermediateits ends at points substantially equi-distant from the vane center toleave the central area of the vane free of preset deformation; a firstterminal on said base; an elongated electrically conductive bracketsecured to said vane at a vane mounting point spaced laterally from saiddeforma tion, and secured at its other end to said first terminal; anexpansible high resistance electric conductor secured at each end tosaid vane adjacent the outer ends of said deformation under tension andparallel to said deformation to bend said vane to a stress-deformedposition in which the vane is bent along the other diagonal of the vane;said vane, upon a predetermined expansion of said conductor, snapping toa preset restored position in which the vane is bent along saiddeformation; the free portion of the vane, during such snapping action,pivoting about such mounting point, a corner of said vane movingsubstantially, relative to the vane mounting point, during suchsnapping; a second terminal on said base; a first contact mounted ininsulated relation on said bracket in alignment with said conductor; asecond contact connected to said conductor and normally engaged withsaid first contact; said contacts being disengaged upon snapping of thevane to such preset restored position; and an elongated strip of springmetal extending across said vane and secured at one end to said cornerfor movement therewith, and set into vibration each time the vane snapsto product an audible indication of snapping of the vane, the free endof said strip being adjacent the diagonally opposite vane corner.

References Cited in the file of this patent UNITED STATES PATENTS

